XHTML is the attempt to purify the traditional mishmash of HTML standards, separating content from appearance, and to create a more elegant solution, for a more civilized age.
That's great in theory - but unless you're armed with a plethora of cross-browser scripts and an iron will, moving to XHTML 1.0 Strict is a hard, bumpy road. And often one with little discernable gain. Did you know you can't use target attributes in link tags? Or alignment tags? Ok, so the alignment tags is a non-issue - we can do the same with CSS styles. But how, pray tell, do we achieve the feats we take for granted in HTML - target="_blank" ?